2College of Pharmacy, Western University of Health Sciences, Pomona, CA, USA

harlan.krumholz{at}yale.edu

At best, and bearing in mind missing data, the drug shortens flu symptoms by a day

In the midst of a worse than average influenza season, clinicians are increasingly prescribing antiviral agents, especially oseltamivir (Tamiflu). Oseltamivir, an oral neuraminidase inhibitor, was first approved for use by the US Food and Drug Administration in 1999. It is indicated “for the treatment of acute, uncomplicated illness due to influenza infection in patients 2 weeks of age and older who have been symptomatic for no more than two days,” and, “for the prophylaxis of influenza in patients 1 year and older,” with similar indications worldwide. Despite these broad indications, some government agencies promote even wider use. For instance, the website of the US Department of Health and Human Services states that oseltamivir may prevent serious complications of flu, and the US Centers for Disease Control and Prevention’s website states that early antiviral treatment may reduce the risk of complications of flu and death.12 Business analysts expect rising sales of oseltamivir to reach $750m (£474m; €562m) this year alone.3

Despite such enthusiasm, some basic questions remain unanswered, including the most crucial: what do we really know about oseltamivir’s effectiveness and who benefits from treatment? With the huge number of people affected and such remarkable sales, the evidence to support the …